Here some baremetal examples for malloc:
https://github.com/rsta2/circle/blob/ma ... /alloc.cpp
https://github.com/vanvught/rpidmx512/b ... c/malloc.c
The malloc is independent of the MMU.
In general, all the GPIO pins on the external header are directly connected to the SoC. At any time we should be careful in direct controlling of external devices.
Controlled by I2C or SPI -> http://www.bitwizard.nl/shop/expansion-boards/BigRelay